well....this is a lesson to learn....my dad used to tell me "whenever you loan money to anybody, loan them as much as you can afford and not wanting the money back!"
I don't know about your relationship and how long you guys are together....but I won't loan this much money till I'm sure he gives money back, or I loan small amount that I don't care if he doesn't give it back....I hate to go and ask for my money....he should be responsible for that....
Just ask him if you can get your money back....or if he can pay you off in several payments....
take care
Marjan